Apple announced over the weekend it will require all new watchOS apps for the Apple Watch to be native, aka operate independently from an iPhone. The announcement came ahead of its WWDC conference in June.
In a blog post, Apple detailed by June 1, 2016 that all apps submitted to the App Store will need to be built with the watchOS 2 SDK -- a software that added native app support in September 2015.
This doesn't mean current watchOS offerings on the App Store will need to be native, but as competition in the smart watch space heats up, developers will need to be competitive. Not only does it make apps run smoother, but saves battery life.
Native app support for the Apple Watch is a big deal, as the wearable operates as its own machine, rather than having to be tethered to an iPhone. It can make tricky situations, like a run, where your phone isn't need, smoother with an Apple Watch on your wrist.